The Casimir energy anomaly for a point interaction

Abstract

The Casimir energy for a massless, neutral scalar field in presence of a point interaction is analyzed using a general zeta-regularization approach developed in earlier works. In addition to a regular bulk contribution, there arises an anomalous boundary term which is infinite despite renormalization. The intrinsic nature of this anomaly is briefly discussed.

5 pages. To appear in the special issue of Mod.Phys.Lett.A containing the Proceedings of the 4th Casimir Symposium (St.Petersburg, June 24-28, 2019)